“This is a reminder that vigilance must be maintained by ensuring that tailings dams continue to be properly designed, constructed, maintained and monitored to prevent such occurrences,’’ Jammal said.

Recipients of the letter have been ordered to take the following steps:

• review the causes of the tailings dam breach at Mt. Polley mine and confirm that the safety
case for the tailings dam at your facility remains valid;
• confirm and demonstrate that all necessary operations, inspections and monitoring have been
conducted in compliance with your license and license conditions handbook;
• confirm that the mitigation measures are in place to mitigate breach accidents; and
• report on any identified gaps and the associated plans to address them.

The recipients have been told to respond to the request by September 15, 2013.